As a conventional surface-enhanced Raman scattering unit, one equipped with a minute metal structure for generate surface-enhanced Raman scattering (SERS) has been known (see, for example, Patent Literature 1 and Non Patent Literature 1). In such a surface-enhanced Raman scattering unit, when a sample to be subjected to Raman spectroscopy is brought into contact with the minute metal structure and is irradiated with excitation light in this state, surface-enhanced Raman scattering occurs, whereby Raman scattering light enhanced by about 108 times, for example, is released.